Electron cooling and Debye-Waller effect in photoexcited bismuth

By means of first principles calculations, we computed the effective electron-phonon coupling constant $G_0$ governing the electron cooling in photoexcited bismuth. $G_0$ strongly increases as a function of electron temperature, which can be traced back to the semi-metallic nature of bismuth. We also used a thermodynamical model to compute the time evolution of both electron and lattice temperatures following laser excitation. Thereby, we simulated the time evolution of (1 -1 0), (-2 1 1) and (2 -2 0) Bragg peak intensities measured by Sciaini et al [Nature 458, 56 (2009)] in femtosecond electron diffraction experiments. The effect of the electron temperature on the Debye-Waller factors through the softening of all optical modes across the whole Brillouin zone turns out to be crucial to reproduce the time evolution of these Bragg peak intensities

Schooling effects and earnings of French University graduates: school quality matters, but choice of discipline matters more

Our aim in this article is to study the relation between earnings of French universities graduates and some characteristics of their universities. We exploit data from the Céreq's "Génération 98" survey, enriched with information on university characteristics primarily from the ANETES (yearbook of French institutions of higher education). We employ multilevel modeling, enabling us to take advantage of the natural hierarchy in our separate datasets, and thus to identify, and even to measure potential effects of institutional quality. Since we take into account many individual students characteristics, we are able to obtain an income hierarchy among the different disciplines : students who graduated in science, economics or management obtain the highest earnings. Below them, we and students who graduated in law, political science, communication or language and literature, while the ones who graduated in social studies earn the lowest incomes. On the institutional level, we need two significant quality effects : the rest is from the socioeconomic composition of the university's student population, and the second effect is from the university's network in the job market. These last two results remain stable when we examine subsamples of universities according to their dominant teaching fields, except for universities that are particularly concentrated in science.Demand for schooling, educational economics, human capital, salaries wage differentials, school choice

Trajectories from public sector of research to private sector : an analysis using french data on young PhD graduates

The organisation of research is a powerful factor structuring the labour market for recent doctorate recipients. The queue for permanent research positions in the academic sector has created a specific labour market for young doctorates, characterised by a proliferation of postdoctoralprogrammes and fixed-term contracts. In that specific context, our paper deals with the way the young PhD graduates enter the labour market, the way they get a job as researcher in the private or public sector and how much the return of the job mobility from the public academic sector to the private sector is. Using a longitudinal survey provided by the Cereq, our results suggest that even if nearly the half of the cohort has a direct access to jobs in the research sector (private or public), 20% remain in trajectories dominated by under-qualifiedjobs or recurrent unemployment. Our empirical investigation show a negative or non significant returns of the job mobility from the public academic sector to the private sector.Marché du travail; Insertion professionnelle; Post Doctorant; Jeune; Mobilité professionnelle; France

Does vocational training help transition from university to work ?: The 'new French Vocational Bachelor degree'

International audienceThis article analyses whether graduates in university vocational courses benefited from better labour market outcomes in France than those in academic courses. We focus on bachelor degrees in France, comparing 'general' or 'academic' degrees with 'vocational' degrees. The vocational bachelor degree was created in 1999 in the continuity of the education policy of expanding the number of vocational courses in French universities and in the framework of the Bologna Process. It aimed to lead to a new qualification at the intermediate level between the qualified technicians' diplomas and the engineering or senior management diplomas. We use a French survey on higher education leavers in 2001 who were interviewed in 2004. In order to take into account the selection in the vocational track, we applied statistical methods which allow us to compare graduates with similar characteristics. Our results show that education mismatch is less great for vocational bachelor graduates, which is coherent with the idea that the vocational track better responds to employers' needs. In addition, we find empirical evidence that vocational bachelors tend to be associated with higher pay even after accounting for the heterogeneity of students. Our last findings suggest that the university-employer link specifically developed for the vocational bachelor course influences the way vocational graduates find their job: they are significantly more likely to use university-based contacts to obtain their first job